The knowledge provided by this project contributes to the policy-making concerning speed and speed control by, among other matters, providing insight into the most relevant road types circumstances for controlling speed; and establishing safe and credible speed limits. This while taking the environment and flow goals into account.
The project integrates existing knowledge and generates fresh knowledge about the relation between speed, speed distribution, and crash rate on various Netherlands roads under a variety of traffic circumstances; and about features that influence the credibility of speed limits.
Speed is one of the core problems in road safety nowadays. This is explained, on the one hand, by the safety influence of driving and collision speeds and, on the other hand, by the fact that our current instruments that should lead to controlled driving speeds do not seem to be working properly, and large groups of people who continue to drive too fast and at unsuitable speeds. This project analyses further the relation between speed, speed distribution, and road safety. Research will also be done about the credibility to drivers of various speed limit systems and the elements that determine credibility. Specifically, answers will be looked for to the following questions:
- What is the relation between speed, speed distribution, and crash rate on various road types?
- What are safe speed limits and what circumstances influence them (external circumstances, road features, collision types, vehicle types)?
- Which elements and features determine the credibility of speed limits?
The first step is deepening the theory. This will be done with a literature study of available and missing knowledge about the relation between speed, speed distribution, and safety and the advantages and disadvantages of various research methods to complete this knowledge. In addition and in a more general sense, an approach will be developed about the problem of speed and speed control and the (innovative) elements that can play a role. This leads to a concretisation of the follow-up research in which the feasibility will, of course, be taken into account. Currently, the idea is to analyse available speed data linked to crash data and (broad) road and traffic features. In order to determine the credibility of the present and alternative speed limit systems, there will be a questionnaire for road users. This may be supplemented by video or simulation research and/or traffic observations. The traffic simulations will be used to estimate the road safety consequences of various speed limit systems; also taking any environmental and flow effects into consideration.